In order to convict someone of driving under the influence (DUI) of alcohol or drugs, a prosecutor must prove beyond a reasonable doubt that the driver had impaired abilities while operating the vehicle. If someone has a blood alcohol content (BAC) over 0.08 percent, the law presumes that the driver is under the influence. However, many people with a BAC under 0.08 percent or with an unknown BAC still get arrested on suspicion of DUI. Officers do not have to base probable cause for an arrest solely on a chemical test showing a BAC, especially if they suspect a drug-related DUI. There are many different ways police can determine that a driver is under the influence.
An officer’s determinations are extremely important in a subsequent DUI case. The prosecutor will rely on an officer’s basis for an arrest and reports to use as evidence to convict you of DUI. The following are some ways officers decide when to arrest you.
Observations
Police reports commonly contain an account of the arresting officer’s observations at the traffic stop that led them to suspect a possible DUI. Some observations of alcohol impairment include:
- Slurred words
- Stumbling
- Nodding off
- Bloodshot or watery eyes
- The smell of alcohol
- Open containers in the vehicle
Some signs of possible drug impairment that officers regularly cite include:
- Bloodshot or glassy eyes
- The smell of marijuana
- Disorientation
- Talking fast, moving around, or unnaturally high energy
- Drowsiness
Alcohol and different types of drugs affect each person in a different way. Therefore, officers will cite any possible observations of intoxication they can. Sometimes, such characteristics may occur due to fatigue, illness, or other completely legal factors. Our defense attorneys closely examine police reports and challenge officers regarding their alleged observations of impairment.
Field Sobriety Tests
If police officers suspect you may be intoxicated, they may request that you exit the car and participate in one or more field sobriety tests (FSTs). The National Highway Traffic Safety Administration (NHTSA) sets out three standardized FSTs for officers to rely on, which include:
- Walk and turn
- Horizontal gaze nystagmus
- One leg stand
During these tests, officers should be trained to take note of many factors and behaviors of a subject, including the ability to follow directions, ability to balance, involuntary reactions in the eyes, and more. If you “fail” one or more FSTs, an officer can use that as probable cause to make an arrest.
One problem with FSTs is that the driver is already in an inherently stressful situation—whether they were drinking or not. Police encounters can be intimidating, and pressure or nervousness can cause an FST participant to make mistakes, even though they were not under the influence. Some officers also do not have the proper training to conduct FSTs or fail to conduct the tests in accordance with the required standards. Our lawyers regularly challenge FST evidence in DUI cases.
Breath Tests
Often, if an officer suspects you have been drinking, they will request that you submit a breath sample for a breath test. This test involves blowing into a device called a breathalyzer, which then estimates your BAC based on the amount of alcohol in your breath. There is currently no approved breathalyzer to detect recent drug use in the United States, so these tests currently only apply when an officer suspects drunk driving.
Illinois has an implied consent law that states any person who drives or physically controls a motor vehicle automatically consents to submitting a breath sample if the officer has sufficient justification to request a test. While you can always refuse to comply, a refusal can result in the automatic suspension of your driver’s license, despite the outcome of a DUI case.
Breath tests can be inaccurate and unreliable for many reasons. Our attorneys regularly challenge breath test results for the following reasons, among others:
- Improperly calibrated equipment
- Untrained officers
- Improper administration of the test
- Not allowing the required waiting period prior to the test
- Electronic interference by radio frequency transmissions
- The subject’s recent exposure to varnish, oil-based paint, gasoline, or other chemicals that can lead to a false-positive
- Health conditions such as gastroesophageal reflux disease (GERD) or diabetes that can increase acetone or breath alcohol levels
- Inflated mouth alcohol levels
- Improperly handled breath samples in forensic labs
Blood Tests
If you are under arrest and at the police station, officers may request that you submit a blood sample to measure your BAC or to see if there are drugs in your system. Similarly to a breath test, implied consent laws mandate that drivers agree to such testing. While prosecutors rely heavily on blood test results in DUI cases, there are several reasons these tests may be inaccurate or may not indicate that you were driving under the influence:
- The forensic lab made errors handling or testing the blood sample
- Drugs can remain in your system for days or weeks after using, so levels of drugs in your system do not necessarily mean you used drugs in the past few hours before you drove
The above are all ways that police can claim you drove under the influence of alcohol or drugs. For each type of evidence, our skilled criminal defense lawyers know ways to challenge the assertions and test results. Often, successfully questioning the reliability of police observations, FST results, or chemical test results can result in a dismissal or acquittal in a DUI case.
Contact Our DuPage County DUI Defense Attorneys at Kent Law, L.L.C., Right Away
Anyone facing DUI charges also faces penalties including fines, license suspension, probation, or even jail time. It is imperative that you contact a qualified criminal defense firm as soon as possible after your arrest so we can begin building an aggressive defense.
Officers are always on the lookout for impaired drivers and often make mistakes and wrongful arrests, which can result in wrongful charges. If you need defense representation in DuPage County, call Kent Law, L.L.C., at (630) 474-8000 as soon as possible.